Dr Jurriaan Ton of Sheffield University
Plants have evolved diverse strategies to resist pests and diseases. Apart from their innate immune system that controls pre-programmed defence reactions, plants can also enhance the responsiveness of their immune system after sensing selected signals in their environment, a phenomenon commonly referred to as defence priming.
We have identified a novel regulatory gene of defence priming, which encodes a putative receptor protein of the chemical plant resistance activator beta-aminobutyric acid (BABA). Further experiments revealed that this protein controls disease resistance and plant growth repression via separate pathways, creating new opportunities to separate the benefits of defence priming from its costs on plant growth.
When investigating the durability of defence priming in Arabidopsis, we discovered that disease-exposed Arabidopsis can transmit defence priming epigenetically to their progeny, thereby providing transgenerational adaptation to disease pressure. In a parallel research project on the role of secondary metabolites in maize innate immunity, we found an unexpected signalling role for apoplastic benzoxazinoids in the regulation of callose deposition during the early stages of attack by aphids and pathogenic fungi.
Below ground, exudation of benzoxazinoids was found to recruit plant-beneficial Pseudomonas putida bacteria that can prime the leaves for wound-inducible defences. We conclude that the plant immune system encompasses a highly adaptive regulatory system that governs responses at different levels and time scales, ranging from transiently expressed defence reactions at the sites of attack to long-lasting epigenetic modifications of defence genes and recruitment of disease-suppressing soil microbes.
Links:
[1] https://www.hutton.ac.uk/staff/nick-birch